On October 16, 1918, while in battle at Côté de Chatillion, while trying to eliminate a machine gun nest, Neibaur became surrounded by 15 German soldiers.

Afflicted by the Great Depression, Neibaur had little money and could not feed his family, which caused him to send his medals to Congress with a note stating, "I cannot eat them."

[1]: xxiii Neibaur enlisted in the Idaho National Guard on March 30, 1917, a week before the April 6 United States declaration of war against Germany.

[1]: 192  He served in the Rocky Mountain northwest, guarding tunnels and railroad bridges until October 1917 when he and his 2nd Idaho Infantry Regiment were ordered to Camp Mills, Long Island.

[4] After completing training and organization at Camp Merritt, New Jersey, the division deployed to France, where it provided replacement troops for other units of the American Expeditionary Force (AEF).

In early September General John Pershing, commander of the AEF, received permission to "reduce" the salient at Saint-Mihiel, southeast of Verdun.

[1]: 104–105  Within days, the crumbling German army was thrown back and the salient was reduced causing a "straightening" of the front line.

[1]: 112–120 On October 16, 1918, the American attacks captured Còte de Châtillon, though there remained several pockets of German units and many isolated machine gun positions.

[1]: 121  Neibaur along with two other soldiers, an observer and a loader, volunteered to flank and remove a network of machine guns just over a hundred yards from "M" Company and 3rd Battalion's hastily occupied positions.

[1]: 125 After his automatic rifle jammed, Neibaur discarded it and tried to crawl or run downhill some 100 yards to friendly lines, during which he was wounded a fourth time, this one in the hip, and fell unconscious.

[1]: 126  He crawled to it and as he did so, some of the Germans charged him with bayonets, four of whom he killed immediately with his pistol, and eleven of whom he captured and led to American lines.

[9] On February 9, 1919, at the AEF headquarters at Chaumont, France, Pershing presented the Medal of Honor to him, along with a dozen other officers and soldiers.

"[1]: 160 [10] In 1919, Pershing included Neibaur in his "Immortal Ten" list of World War I soldiers whose wartime feats best exemplified the traits of heroism and personal courage.

US Senator William Borah of Idaho attempted to pass a law in the US Congress promoting Neibaur to the rank of major in the regular army, and then placing him on the retired list.

[16] United States of America: France: Italy: Montenegro: Service Medal(s): Official Campaign Designations: Information retrieved from Place the Headstones Where They Belong.

[17] Citation: On the afternoon of 16 October 1918, when the Cote-de-Chatillion had just been gained after bitter fighting and the summit of that strong bulwark in the Kriemhilde Stellung was being organized, Pvt.

As he gained the ridge he set up his automatic rifle and was directly thereafter wounded in both legs by fire from a hostile machinegun on his flank.

The advance wave of the enemy troops, counterattacking, had about gained the ridge, and although practically cut off and surrounded, the remainder of his detachment being killed or wounded, this gallant soldier kept his automatic rifle in operation to such effect that by his own efforts and by fire from the skirmish line of his company, at least 100 yards in his rear, the attack was checked.